$re = '/\d+(?!.*\d)/m';
$str = '0 Joseon Mun1JSM
1 Crazy pepe2CRAZYPEPE
2 NOOT (BRC-20)3NOOT
3 nomeme4NOMEME
4 Shrekt5HREK
5 WODIU6WODIU
6 Mr Bean Inu7MRBEAN
7 CMC DOGE8CMCDOGE
8 GEKE9GEKE
9 BLAZE TOKEN10BLZE
10 Toad Killer11$TOAD
11 LANDWOLF12LANDWOLF
12 Fonzy13FONZY
13 Iron Pepe14IPEPE
14 Bruv15BRUV';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php